Label

Element

Value

Osterweis Total Return Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Osterweis Total Return Fund

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Osterweis Total Return Fund (the “Fund”) seeks to preserve capital and attain long-term total returns through a combination of current income and moderate capital appreciation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses of the Fund

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

Dec. 31, 2018

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example above, affect the Fund’s performance. During the most recent fiscal period ended March 31, 2017, the Fund’s portfolio turnover rate was 27% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

27.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

Other Expenses and Acquired Fund Fees and Expenses are based on estimated customary Fund expenses for the current fiscal year.

Acquired Fund Fees and Expenses, Based on Estimates [Text]

rr_AcquiredFundFeesAndExpensesBasedOnEstimates

Other Expenses and Acquired Fund Fees and Expenses are based on estimated customary Fund expenses for the current fiscal year.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the Expense Cap only in the first year).

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Under normal circumstances, the Fund intends to invest at least 80% of its net assets in investment grade fixed income instruments and derivatives thereon. These fixed income instruments may include, but are not limited to, U.S. Federal and Agency obligations, investment grade corporate debt, mortgage backed securities (including privately issued mortgage backed securities), asset backed securities, floating-rate debt, convertible debt, collateralized debt, municipal debt, foreign debt (including in emerging markets) and/or depositary receipts, sovereign debt and preferred stock. Of the government agency securities, the Fund expects to hold significant amounts of Treasuries and mortgage-backed securities guaranteed by the Government National Mortgage Association (GNMA) or government-sponsored enterprises, such as mortgages backed by the Federal National Mortgage Association (FNMA) or the Federal Home Loan Mortgage Corporation (FHLMC). Un-rated securities may be deemed investment grade, particularly in the case of government agency securities and their derivatives. Additionally, the Fund may hold up to 20% of its assets in high yield debt securities (“junk bonds”).

The Fund’s allocation among various fixed income instruments is based on the portfolio managers’ assessment of opportunities for total return relative to the risk of each type of investment. The Fund does not target a specific average maturity or duration (duration is a measure of price sensitivity related to changes in interest rates). The Fund may invest in fixed income instruments of any maturity or duration. Duration can change based on market fluctuations. The Fund may invest without limitation in derivative instruments including swaps, options and futures. The Fund’s primary use of derivatives will be to refine interest rate exposure and/or hedge various other investment exposures. Although the use of derivatives can involve leverage, the Fund does not intend to use derivatives to amplify its net investment exposure. Separately, the Fund may invest up to 20% of its assets in foreign debt (including in emerging markets) and/or depositary receipts. The Fund may also invest in other investment companies and exchange-traded funds (“ETFs”), for the purpose of gaining exposure to certain markets while maintaining liquidity.

The Adviser may sell a security when it believes doing so is appropriate and consistent with the Fund’s investment objective and policies or when conditions affecting relevant markets, particular industries or individual issues warrant such action, regardless of the effect on the Fund’s portfolio turnover rate.

Risk [Heading]

rr_RiskHeading

Principal Investment Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

There is the risk that you could lose all or a portion of your investment in the Fund. The following riskscould affect the value of your investmentin the Fund:

· Currency Risk: Fluctuations in currency exchange rates may adversely affect the value of the Fund’s investments in foreign securities as well as the value of the Fund’s investments in domestic securities whose issuers earn at least a portion of their revenue in foreign currency.

· Debt Securities Risks:

- Credit Risk: The risk that an issuer of a fixed income security will fail to make interest payments or repay principal when due, in whole or in part. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in a security’s credit rating may affect a security’s value. In addition, investments in sovereign debt involves a heightened risk that the issuer responsible for repayment of the debt may be unable or unwilling to pay interest and repay principal when due, and the Fund may lack recourse against the issuer in the event of default. Investments in sovereign debt are also subject to the risk that the issuer will default independently of its sovereign. Below investment grade securities (high yield/junk bonds) have speculative characteristics, and changes in economic conditions or other circumstances are more likely to impair the ability of issuers of those securities to make principal and interest payments than is the case with issuers of investment grade securities.

- Defaulted Securities Risk: The risk of the uncertainty of repayment of defaulted securities (e.g., a security on which a principal or interest payment is not made when due) and obligations of distressed issuers.

- Extension Risk: The risk that if interest rates rise, repayments of principal on certain debt securities, including, but not limited to, floating rate loans and mortgage-related securities, may occur at a slower rate than expected and the expected maturity of those securities could lengthen as a result. Securities that are subject to extension risk generally have a greater potential for loss when prevailing interest rates rise, which could cause their values to fall sharply.

- Interest Rate Risk: The risk that debt instruments will change in value because of changes in interest rates. The value of an instrument with a longer duration (whether positive or negative) will be more sensitive to changes in interest rates than a similar instrument with a shorter duration. Bonds and other debt instruments typically have a positive duration. The value of a debt instrument with positive duration will generally decline if interest rates increase. Certain other investments, such as interest-only securities and certain derivative instruments, may have a negative duration. The value of instruments with a negative duration will generally decline if interest rates decrease. Inverse floaters, interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments. As of the date of this Prospectus, interest rates in the U.S. are at or near historically low levels, increasing the exposure of bond investors to the risks associated with rising interest rates.

- Prepayment Risk: The risk that the issuer of a debt security, including floating rate loans and mortgage-related securities, repays all or a portion of the principal prior to the security’s maturity. In times of declining interest rates, there is a greater likelihood that the Fund’s higher yielding securities will be pre-paid with the Fund being unable to reinvest the proceeds in an investment with as great a yield. Prepayments can therefore result in lower yields to shareholders of the Fund.

· Derivatives Risk: The risk of investing in derivative instruments (such as futures, swaps and structured securities), including liquidity, interest rate, market, credit and management risks, mispricing or valuation complexity. Changes in the value of the derivative may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. The Fund’s use of derivatives may result in losses to the Fund, a reduction in the Fund’s returns and/or increased volatility. Over-the-counter (“OTC”) derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. For derivatives traded on an exchange or through a central counterparty, credit risk resides with the creditworthiness of the Fund’s clearing broker, or the clearinghouse itself, rather than to a counterparty in an OTC derivative transaction. Changes in regulation relating to a mutual fund’s use of derivatives and related instruments could potentially limit or impact the Fund’s ability to invest in derivatives, limit the Fund’s ability to employ certain strategies that use derivatives and/or adversely affect the value or performance of derivatives and the Fund.

· Foreign Securities and Emerging Markets Risk: Investing in foreign securities may involve increased risks due to political, social and economic developments abroad, and differences between U.S. and foreign regulatory practices. These risks can be elevated in emerging markets. Investments in emerging markets are generally more volatile than investments in developed foreign markets. Given the global interrelationships of today’s economy, volatility or threats to stability of any significant currency, such as occurred in the recent past with the European Monetary Union, or significant political instability, may affect other markets and affect the risk of an investment in the Fund.

· General Market Risk: Economies and financial markets throughout the world are becoming increasingly interconnected, which increases the likelihood that events or conditions in one country or region will adversely impact markets or issues in other countries or regions.

· Investment Company and Exchange-Traded Fund Risk: Investing in other investment companies involves the risk that an investment company or other pooled investment vehicle, including any ETFs or money market funds, in which the Fund invests will not achieve its investment objective or execute its investment strategies effectively or that significant purchase or redemption activity by shareholders of such an investment company might negatively affect the value of the investment company’s shares. The Fund must pay its pro rata portion of an investment company’s fees and expenses.

· Leverage Risk: Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Fund to greater risk and increase its costs. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet any required asset segregation requirements. Increases and decreases in the value of the Fund’s portfolio will be magnified when the Fund uses leverage.

· Liquidity Risk: Securities purchased by the Fund may become illiquid particularly during periods of market turbulence. Illiquid investments may be more difficult to trade and value than liquid ones and if the Fund is forced to sell these investments promptly to meet redemption requests or for other needs, the Fund may incur a loss.

· Management Risk: The risk that the Adviser may fail to implement the Fund’s investment strategies and meet its investment objective.

· Mortgage-Related and Other Asset-Backed Securities Risk: The risk that borrowers may default on their mortgage obligations or the guarantees underlying the mortgage-backed securities will default or otherwise fail and that, during periods of falling interest rates, mortgage-backed securities will be called or prepaid, which may result in the Fund having to reinvest proceeds in other investments at a lower interest rate. During periods of rising interest rates, the average life of a mortgage-backed security may extend, which may lock in a below-market interest rate, increase the security’s duration, and reduce the value of the security. Enforcing rights against the underlying assets or collateral may be difficult, or the underlying assets or collateral may be insufficient if the issuer defaults. The values of certain types of mortgage-backed securities, such as inverse floaters and interest-only and principal-only securities, may be extremely sensitive to changes in interest rates and prepayment rates.

· Municipal Securities Risk: Investing in various municipal securities may involve risk related to the ability of the municipalities to continue to meet their obligations for the payment of interest and principal when due. A number of municipalities have had significant financial problems recently, and these and other municipalities could, potentially, continue to experience significant financial problems resulting from lower tax revenues and/or decreased aid from state and local governments in the event of an economic downturn. This could decrease the Fund’s income or hurt the ability to preserve liquidity.

· New Fund Risk: The Fund is new and there can be no assurance that the Fund will grow to or maintain an economically viable size.

· Preferred Securities Risk: The risk that: (1) certain preferred stocks contain provisions that allow an issuer under certain conditions to skip or defer distributions; (2) preferred stocks may be subject to redemption, including at the issuer’s call, and, in the event of redemption, the Fund may not be able to reinvest the proceeds at comparable or favorable rates of return; (3) preferred stocks are generally subordinated to bonds and other debt securities in an issuer’s capital structure in terms of priority for corporate income and liquidation payments; and (4) preferred stocks may trade less frequently and in a more limited volume and may be subject to more abrupt or erratic price movements than many other securities.

· U.S. Government and Agency Issuer Risk: Treasury obligations may differ in their interest rates, maturities, times of issuance and other characteristics. Obligations of U.S. Government agencies and authorities are supported by varying degrees of credit but generally are not backed by the full faith and credit of the U.S. Government. No assurance can be given that the U.S. Government will provide financial support to its agencies and authorities if it is not obligated by law to do so.

Risk Lose Money [Text]

rr_RiskLoseMoney

There is the risk that you could lose all or a portion of your investment in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

Because the Fund recently commenced operations, it does not have a full calendar year of performance to compare against a broad measure of market performance. Accordingly, performance information is not available. Performance information will be available after the Fund has been in operation for one calendar year. At that time, the performance information will provide some indication of the risks of investing in the Fund by comparing it against a broad measure of market performance. Updated performance information is available on the Fund’s website at www.osterweis.com or by calling the Fund toll-free at (866) 236-0050.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

Because the Fund recently commenced operations, it does not have a full calendar year of performance to compare against a broad measure of market performance. Accordingly, performance information is not available.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

(866) 236-0050

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.osterweis.com

Osterweis Total Return Fund | Investor Class

Risk/Return:

rr_RiskReturnAbstract

Shareholder Fees (fees paid directly from your investment)

rr_ShareholderFeeOther

none

Management Fees

rr_ManagementFeesOverAssets

0.45%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

2.10%

^[1]

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.07%

^[1]

Total Annual Fund Operating

rr_ExpensesOverAssets

2.62%

Fee Waiver and/or Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(1.80%)

Total Annual Fund Operating Expenses

rr_NetExpensesOverAssets

0.82%

^[2]

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 84

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 643

[1] Other Expenses and Acquired Fund Fees and Expenses are based on estimated customary Fund expenses for the current fiscal year.

[2] Osterweis Capital Management, LLC (the "Adviser") has contractually agreed to reduce its fees and/or pay Fund expenses (excluding Acquired Fund Fees and Expenses, interest expense in connection with investment activities, taxes and extraordinary expenses) in order to limit Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the Fund to 0.75% of the Fund's average net assets (the "Expense Cap"). The Expense Cap is indefinite, but will remain in effect until at least December 31, 2018. The Agreement may be terminated at any time by the Board of Trustees upon 60 days' written notice to the Adviser, or by the Adviser with consent of the Board. The Adviser is permitted, with Board approval, to be reimbursed for fee reductions and/or expense payments made in the prior three years. This reimbursement may be requested if the aggregate amount actually paid by the Fund toward operating expenses for such period (taking into account any reimbursement) does not exceed the lesser of the Expense Cap in place at the time of waiver or at the time of reimbursement.